// you can use print for debugging purposes, e.g.
// print "this is a debug message\n";

function solution($X, $Y, $D) {
     $r=0;

        if($Y>$X)
        {   
            $r=($Y-$X)/$D;
            if(($X+($r*$D)) < $Y) $r++;
        }

        return $r;
}

// you can use print for debugging purposes, e.g.
// print "this is a debug message\n";

function solution($X, $Y, $D) {
     $r=0;

        if($Y>$X)
        {   
            $r=($Y-$X)/$D;
            if(($X+($r*$D)) < $Y)
                $r++;
        }

        return round($r);
}

// you can use print for debugging purposes, e.g.
// print "this is a debug message\n";

function solution($X, $Y, $D) {
     $r=0;

        if($Y>$X)
        {   
            $r=($Y-$X)/$D;
            if(($X+($r*$D)) < $Y)
                $r++;
        }

        echo round($r);
}

// you can use print for debugging purposes, e.g.
// print "this is a debug message\n";

function solution($X, $Y, $D) {
     $r=0;

        if($Y>$X)
        {   
            $r=($Y-$X)/$D;
            if(($X+($r*$D)) < $Y)
                $r++;
        }

        echo intval(round($r));
}

// you can use print for debugging purposes, e.g.
// print "this is a debug message\n";

function solution($X, $Y, $D) {
     $r=0;

        if($Y>$X)
        {   
            $r=($Y-$X)/$D;
            if(($X+($r*$D)) < $Y)
                $r++;
        }

        echo intval(round($r));
}

// you can use print for debugging purposes, e.g.
// print "this is a debug message\n";

function solution($X, $Y, $D) {
     $r=0;

        if($Y>$X)
        {   
            $r=($Y-$X)/$D;
            $r=round($r);
            if(($X+($r*$D)) < $Y)
                $r++;
        }

        echo intval(round($r));
}

// you can use print for debugging purposes, e.g.
// print "this is a debug message\n";

function solution($X, $Y, $D) {
    $left = ($Y - $X) / $D;
    return $left <> intval($left) ? intval($left + 1) : intval($left);
}

// you can use print for debugging purposes, e.g.
// print "this is a debug message\n";

function solution($X, $Y, $D) {
     $r=0;

        if($Y>$X)
        {   
            $r=($Y-$X)/$D;
            $r=round($r);
            if(($X+($r*$D)) < $Y)
                $r++;
        }

        return intval(round($r));
}

// you can use print for debugging purposes, e.g.
// print "this is a debug message\n";

function solution($X, $Y, $D) {
     $r=0;

        if($Y>$X)
        {   
            $r=($Y-$X)/$D;
            //$r=round($r);
            if(($X+($r*$D)) < $Y)
                $r++;
        }

        return intval(round($r));
}

// you can use print for debugging purposes, e.g.
// print "this is a debug message\n";

function solution($X, $Y, $D) {
     $r=0;

        if($Y>$X)
        {   
            $r=($Y-$X)/$D;
            if(($X+($r*$D)) < $Y)
                $r++;
        }

        return intval(round($r));
}

// you can use print for debugging purposes, e.g.
// print "this is a debug message\n";

function solution($X, $Y, $D) {
     $r=0;

        if($Y>$X)
        {   
            $r=($Y-$X)/$D;
            if(($X+($r*$D)) < $Y)
                $r++;
        }

        return intval(round($r));
}

// you can use print for debugging purposes, e.g.
// print "this is a debug message\n";

function solution($X, $Y, $D) {
     $r=0;

        if($Y>$X)
        {   
            $r=($Y-$X)/$D;
            //if(($X+($r*$D)) < $Y)
                //$r++;
        }

        return intval(round($r));
}

// you can use print for debugging purposes, e.g.
// print "this is a debug message\n";

function solution($X, $Y, $D) {
     $r=0;

        if($Y>$X)
        {   
            $r=($Y-$X)/$D;
            //if(($X+($r*$D)) < $Y)
                //$r++;
        }

        return intval(round($r));
}

// you can use print for debugging purposes, e.g.
// print "this is a debug message\n";

function solution($X, $Y, $D) {
     $r=0;

        if($Y>$X)
        {   
            $r=($Y-$X)/$D;
            //if(($X+($r*$D)) < $Y)
                //$r++;
        }

        return intval(round($r));
}

// you can use print for debugging purposes, e.g.
// print "this is a debug message\n";

function solution($X, $Y, $D) {
     $r=0;

        if($Y>$X)
        {   
            $r=($Y-$X)/$D;
            //if(($X+($r*$D)) < $Y)
                //$r++;
        }

        return intval(round($r));
}

// you can use print for debugging purposes, e.g.
// print "this is a debug message\n";

function solution($X, $Y, $D) {
     $r=0;

        if($Y>$X)
        {   
            $r=($Y-$X)/$D;
            //if(($X+($r*$D)) < $Y)
                //$r++;
        }

        return intval(round($r));
}

// you can use print for debugging purposes, e.g.
// print "this is a debug message\n";

function solution($X, $Y, $D) {
     $r=0;

        if($Y>$X)
        {   
            $r=($Y-$X)/$D;
            //if(($X+($r*$D)) < $Y)
                //$r++;
        }

        return intval(round($r));
}

// you can use print for debugging purposes, e.g.
// print "this is a debug message\n";

function solution($X, $Y, $D) {
     $r=0;

        if($Y>$X)
        {   
            $r=($Y-$X)/$D;
            //if(($X+($r*$D)) < $Y)
                //$r++;
        }

        return intval(round($r));
}

// you can use print for debugging purposes, e.g.
// print "this is a debug message\n";

function solution($X, $Y, $D) {
     $r=0;

        if($Y>$X)
        {   
            $r=($Y-$X)/$D;
            //if(($X+($r*$D)) < $Y)
                //$r++;
        }

        return intval(round($r));
}

// you can use print for debugging purposes, e.g.
// print "this is a debug message\n";

function solution($X, $Y, $D) {
     $r=0;

        if($Y>$X)
        {   
            $r=($Y-$X)/$D;
            //if(($X+($r*$D)) < $Y)
                //$r++;
        }

        return intval(round($r));
}

// you can use print for debugging purposes, e.g.
// print "this is a debug message\n";

function solution($X, $Y, $D) {
     $r=0;

        if($Y>$X)
        {   
            $r=($Y-$X)/$D;
            if(($X+($r*$D)) < $Y)
                $r++;
        }

        return intval(round($r));
}

// you can use print for debugging purposes, e.g.
// print "this is a debug message\n";

function solution($X, $Y, $D) {
     $r=0;

        if($Y>$X)
        {   
            $r=($Y-$X)/$D;
            if(($X+($r*$D)) < $Y)
                $r++;
        }

        return intval(round($r));
}

// you can use print for debugging purposes, e.g.
// print "this is a debug message\n";

function solution($X, $Y, $D) {
     $r=0;

        if($Y>$X)
        {   
            $r=($Y-$X)/$D;
            if(($X+($r*$D)) < $Y)
                $r++;
        }

        return intval(round($r));
}

// you can use print for debugging purposes, e.g.
// print "this is a debug message\n";

function solution($X, $Y, $D) {
     $r=0;

        if($Y>$X)
        {   
            $r=($Y-$X)/$D;
            $r=floor($r);
            if(($X+($r*$D)) < $Y)
                $r++;
        }

        return intval(floor($r));
}

// you can use print for debugging purposes, e.g.
// print "this is a debug message\n";

function solution($X, $Y, $D) {
     $r=0;

        if($Y>$X)
        {   
            $r=($Y-$X)/$D;
            $r=floor($r);
            if(($X+($r*$D)) < $Y)
                $r++;
        }

        return intval(floor($r));
}

// you can use print for debugging purposes, e.g.
// print "this is a debug message\n";

function solution($X, $Y, $D) {
     $r=0;

        if($Y>$X)
        {   
            $r=($Y-$X)/$D;
            $r=floor($r);
            if(($X+($r*$D)) < $Y)
                $r++;
        }

        return intval(floor($r));
}